Chain saws typically include an endless saw chain disposed to articulate around a saw bar comprising various coupled links including cutter links, drive links, and tie straps. The cutter links and tie straps are typically in sliding engagement on bar rails of the saw bar. The cutter links can be used for cutting wood, concrete, ice and other materials.
The cutter links and tie straps which ride on the saw bar rails are generally sized to match the bar rail width/thickness. This allows the bar rail and the respective bottoms of the cutter links and tie straps to wear against each other evenly and keep one or the other from getting a non-worn area known as a “knife edge”. A knife edge is undesirable because it can cause tight joints or burrs or be a source of crack initiation.
The kerf of the saw chain is generally the width of the cut that a chain makes as it cuts through material. It is controlled by the distance from the farthest outside offset dimension of the cutting portion of the cutter link on respective opposite sides of the chain. Making the kerf of the chain as narrow as possible is desirable to minimize the power necessary for cutting. Prior attempts to narrow the Kerf, however, has generally resulted in 1) knife edging occurring on the bar rails and/or the links by using thinner chain components; 2) an unacceptable decrease of kerf to bar clearance; 3) weakening of and/or limiting the length of the bar by virtue of narrowing the bar in conjunction with narrowing the components and/or to maintain a satisfactory kerf to bar clearance; and 4) reducing the cutter offset, which undesirably reduces the amount of clearance between the kerf wall and the bar, thereby negatively affecting the chip flow up the side of the bar and chain.